Übersetzung für "Ersatzkapazität" in Englisch

The equivalent capacity C having the poles k1, k2 and k3 is shown in the circuit diagram of FIG.

The load-independent measurement current I M conveys charges Q to the equivalent capacitor C E .

This should not however have the ultimate effect of allowing BE to acquire more flexibility capacity than it presently has, nor to use this replacement capacity to make profit during the possible overlap period between the end of its construction and the disposal of Eggborough.

In these scenarios, immediate decommissioning after obsolete plants shutdown would ease the construction of replacement capacity on existing nuclear sites.

According to the invention, the tray formed by the epitaxial layer 37 is likewise connected through the resistance R to a reference potential Vref at a high resistance so that a series connection of the two parasitic capacities is obtained which leads to an equivalent capacity which is considerably smaller than the barrier layer capacity or the MOS capacity.

When the maximum frequency fmax is exceeded, the capacitors 12 also carry current due to the opening of the switch 4, and the equivalent capacitance of each phase winding is then diminished by the series connection of the capacitors 11 and 12 in relation to the capacitance of the capacitors 11, to the extent that the resonant frequency is raised to a value lying outside of every operational possibility.

Equation (3) means that a current in the equivalent capacitance is equal to the sum of the load currents, in each case multiplied by the modulation level s np at the first neutral point 31 with respect to the phase of the respective load current.

In the equivalent circuit, the converter bridges are modeled as switches or changeover switches, and the two intermediate-circuit capacitors in the first DC voltage intermediate circuit 3 are combined to form an equivalent capacitance Cnp of the first neutral point 31 .

The one terminal of the transformer TR1 is directly connected to the gate of a field effect transistor T1, while the other terminal is conducted to a substitute capacitance CE.

With a series connection of capacitors, it is known that a substitute capacitance is obtained, which is smaller than the smallest single capacitance, and in the illustrated embodiment the capacitor network must be considered as one capacitor, for instance as a total capacitance 2C.

In embodiments, the link capacitor is modeled as a series interconnection of an equivalent capacitance and an equivalent series resistance and a modeled capacitor current flows across the equivalent series resistance.

The modeled capacitor current can be modeled by using a measured capacitor voltage and the equivalent capacitance CS, wherein a second relationship of the form i Cm =f(u C, CS) is used.

In accordance with the second relationship, for example by taking the time derivative and multiplying it by the first capacitance, the low-frequency component of the modeled capacitor current is inferred.

The link capacitor C is modeled by means of an equivalent capacitance CS and an equivalent resistance ESR, which is assumed to be in series and which is generally frequency-dependent.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a method and a device for determining a temperature progression of a link capacitor of a link converter that contains at least one n-phase inverter.

The method as claimed in claim 1, wherein known measurement current I M is applied to the OLED for determining the equivalent resistance R E, the voltage drop U 1 across the OLED is measured directly after the onset of the measurement current I M before a noteworthy charging voltage can be built up at the equivalent capacitor C E, and

It has already been established to assume a parallel connection of an equivalent capacitor and an equivalent diode, and an equivalent resistor connected in series with this parallel connection, as an equivalent circuit diagram for an OLED.

An embodiment of the method according to the invention includes applying a known measurement current I M, preferably a measurement current pulse, to the OLEDs for determining the equivalent resistance R E, measuring the voltage drop U 1 across the OLED directly after the onset of the measurement current I M, to be precise before a noteworthy charging voltage can be built up at the equivalent capacitor C E, and then calculating the equivalent resistance R E according to the following formula: R E =U 1 /I m . (1)

In particular, the characteristic values of the OLED, which can be used for determining the OLED type and/or OLED dimension, can be the values for the equivalent resistance R E, the equivalent capacitance C E and/or the equivalent diode D E .

The values for the equivalent resistance R E and the equivalent capacitance C E can be determined at a different time from when the values for the equivalent diode D E are determined.

The switch S 1 is closed at time 0, and so the OLED is set to the defined voltage of 0 V and the equivalent capacitor C E does not have any charge either.

Initially, it is only the voltage drop across the equivalent resistor R E that is decisive for the voltage at the measurement point P because the equivalent capacitor C E is initially still without voltage and only charges over time.

The linear increase in the voltage is the result of charging the equivalent capacitor C E and the fact that I M is a load-independent current.

The switch S 2 is reopened at time t 2, resulting in the charging of the equivalent capacitor C E being interrupted and no more charging current flowing through the equivalent resistor R E .

Hence, care has to be taken that the highest charging voltage of the equivalent capacitor C E, applied to the equivalent diode D E, lies below the voltage at which the charging diode D E starts to conduct.

As a result, there is charge balancing between the reference capacitor C R and the equivalent capacitor C E of the OLED.